Alternator Leaks

[garyde]

I had a seal replaced on the front of my Alternator a year ago at Prevost. It was throwing a little oil, not much. Now there is a small amount showing on the back plate, no drips. Do these units ever not leak? It does not look like much, the question is when to have it fixed.
I like to stay on top of these small problems before they get to be bigger ones.:confused:

[Jon Wehrenberg]

I think they all get small visible leaks over time. I usually clean the grease and accumulated dirt off with a solvent or Simple Green when I change the oil. A very tiny leak that makes a black area seems like it is a much bigger leak than it really is. I get the same thing behind the clutch on the AC compressor. I know they should be perfect and leak free, but until I actually see liquid running down I'm reluctant to mess with it.

[Joe Cannarozzi]

Gary I assume you are talking about that gear driven, oil cooled unit that I have on my 8-V but I know you have the 60 Series so yours may be different.

The gasket was leaking on the back plate on mine and what I found was the rear edge of the alt. housing that becomes the mating surface for that back plate is very thin (1/8in). That almost creates a knife to the gasket if that plate is overtightened. That combined with the cork gasket IMO made for a poor design.

If yours is of similar design my suggestion would be do not over tighten when reinstalling a new gasket.

Here is what I had before the repair.
3077

[Will Garner]

Joe,

I was wondering if you might have any pictures of the power steering pump, which I understand on the 8V92 is attached to the transmission bellhousing. After returning from our big trip in June, I went back to the barn a week later. After backing out of the barn, the grandson found a puddle of what to me looked like transmission fluid. I had felt a racheting feel in the steering wheel while backing out. Checked the power steering reservoir and it was empty. Yesterday I filled the reservoir then moved it back in while turning the wheel slightly and the ratcheting feel was gone. Conclusion, leaking power steering hose.

I enjoyed viewing the photos taken and reading of the repairs done on Lloyd's coach. I hope OSHA does not see them!

Hope all is well by you.

[Joe Cannarozzi]

Will where was the puddle exactly.

In the picture above I am in front of the engine up between the axles looking back ate the motor. To the left of the alternator is the air compressor it is blue-green. Just below that is the power steering pump, it too is gear driven. You can barely see it if you open your rear starboard engine door and it is probably the same color as the compressor.

In addition to a possible line leaking, on the pump their is a plunger with an o-ring held in by a roll-pin that is also a potential leak point.

That is a tough one to get at.

[Kevin Erion]

Gary, I know how you feel with small things before they get big. I also just changed the front seal behind the pulley on my 270 AMP alternator. I was very happy to find that it was very easy to do and Prevost, Mira Loma had 6 seal kits in stock. Sounds like that one is kind of common.
The back side is dry now but if I did see a small amount of oil I would call Mira Loma and ask if that is just a gasket, there shouldn't be much oil in the alternator because it drains back into the oil pan. I would do the gasket after the engine sat for a day or so without running to let the oil drain back.

[rfoster]

Gary: I was being aggravated by a small leak on my alternator sometime ago and found four or five little studs in behind the pulley that are secured with maybe 3/8 or 7/16 nuts and I snugged those down about 1/2 turn each and it helped reduce the leak considerably. I still check on a regular basis and will find a small amount of oil, which goes along way when combined with belt dust. I just wipe it off.

Careful not to overtighten, just snug. That is southern for no torque wrench.

[Jon Wehrenberg]

Will,

Running a power steering reservoir out of oil is obviously not the thing to do, but it needs to be put in context.

If it happened on a single trip then the leak is serious and needs attention. But if the level has not been checked in 50,000 miles it could be considerably less serious. A good guide to the degree of seriousness leaks are is if there is any visble drops under the bus. A puddle says something is wrong and it needs to be resolved right away. I don't think you should even drive the bus until that is fixed.

If it is not a hose or hose connection the power steering pump on an 8V92 is not the easiest component to access. Good luck.

[Joe Cannarozzi]

So what I am concluding here is that big 240amp alt on the 60 series is belt driven not gear driven but still oil cooled and not only does it have a gasket and a back plate but a shaft seal behind the pulley too?

Could someone put up a picture. Thanks in advance.

[Jon Wehrenberg]

Here are two, one of the belt driven side and one showing the rear.

[garyde]

Thanks everyone. Yes, mine is belt driven Joe and looks exactly like Jon's photo. I will keep an eye on it. Kevin, I don't see a dip stick or plug for the alternator, should the oil be checked?

[Joe Cannarozzi]

The back of it looks the same for either engine/alternator. No Gary. there is a supply line and a drain, it circulates with the crankcase.

This also means that to get the back plate off the 60 series alt through the battery door is easy but the 8-V requires that you block up the frame and acess it up between the rear-end and tag, sitting up, looking back. It is just a little harder, BEING CARFUL, still an easy fix.

I found loose bolts all over everywhere on our bus, many on the engine and its components. Ours is a "factory" rebuilt but then some shop, who knows who, had to bolt everything back on and in and that is often the brake in the chain, I would like to believe DD factory motors, that have never been tampered with do not display this same shortcoming. Usually they will not (if ya get a good one)

Along with the alt leaks check your exhaust manifold nuts on those 8-V rebuilds. I found loose ones, good way to burn out a exhaust gasket. The bolts for the mounting base for the air compressor were loose and leaking. This is all easy stuff that could be accomplished by most. I had loose and leaking lines at the bell housing for the trans leaking, again, prevo didn't send that down the road like that. Some SCHMUCK was in there.

[Jon Wehrenberg]

Gary,

I think your is the same as mine in that the bearings are supplied oil under pressure and there is a large return line going into the side of the oil pan on the engine. The return is just gravity flow.

[mike kerley]

Jon, I dont know about your slack adjusters, but that is one clean engine!:)

[Ray Davis]

Will, the 8V92 power steering pump has an o-ring seal that seems to go out regularly (every couple of years). Had that issue with my 93 Country Coach.

I happened to take it to Prevost to fix, and it was done quickly with no problem. But, it might be a do-able thing by yourself, if handy.

Do a forum search for o-ring or power steering, and see if it comes up. I'm pretty sure it's been discussed a couple of times here in the forums.

Ray

[Jon Wehrenberg]

Mike, There was a time my slack adjusters were this clean.

After four years of ownership they are a little dirty, so I admit they need a little work again.

[Will Garner]

Ray,

I spoke with Joe C from Chicago last night. He said the same thing. I am getting together with Jon and others to have dinner with Kevin as he comes through Asheville, NC on 8th August. At that time I am acquiring a set of bus jack stands from Jon. I should be trying to find the leak by 15th August. Joe C. says not to drive it so I sure hope I'm handy with this one. There are no repair shops close by where I live.

Thanks for the suggestion. Hope all is well with you and Kathy.

Will

[JIM CHALOUPKA]

You can do it Will. ;):)